Section 2B

1
Section 2B
2-B

• Standardized Units
• Pages 101-112

2
Standardized Unit Systems
2-B

• Metric system (SI)
• Système International
• U.S. customary system (USCS)
• Roots from ancient Middle Eastern civilizations

Unit conversions within systems. Unit conversions
between systems.
3
U.S. Customary System - Lengths
2-B
page101
4
U.S. Customary System - Weights
2-B
page102
5
U.S. Customary System - Volumes
2-B
page102
6
Conversions within USCS
2-B

• Ex1/103 In the Kentucky Derby, horses race 10
  furlongs. How many miles is this?

7
Conversions within USCS
2-B

• Ex1/103 In 20,000 Leagues Under the Sea, does the
  title refer to an ocean depth?

convert marine leagues to miles
8
Conversions within USCS
51/114 If 150 bushels of wheat are traded on one
day, how many cubic inches are traded? how many
cubic feet?
9
International Metric System
2-B

• Invented in France, late 18th century
• Replace many customary units with a few basic
  units
• Simplify conversions by using a base 10 system

10
International Metric System
2-B

• The basic units are
• meter (m) for length
• gram (g) for mass
• second (s) for time
• liter (L) for volume

11
Metric System - Prefixes
2-B
5.23 m
523 cm
.00523 km
12
Conversions within Metric System
2-B

• Convert 19 decimeters to millimeters
• conversion or decimal movement
• 1900 millimeters
• Convert 1378 g to kg
• conversion or decimal movement
• 1.378 kg

13
2-B
USCS - Metric  Conversions USCS - Metric  Conversions
USCS to Metric Metric to USCS
1 in. 2.540 cm 1 cm 0.3937 in.
1 ft 0.3048 m  1 m 3.28 ft
1 yd 0.9144 m 1 m 1.094 yd
1 mi 1.6093 km 1 km 0.6214 mi
1 lb 0.4536 kg 1 kg 2.205 lb
1 fl oz 29.574 mL 1 mL 0.03381 fl oz
1 qt 0.9464 L 1 L 1.057 qt
1 gal 3.785 L 1 L 0.2642 gal
14
Conversions between Metric and USCS

• 60/114 Convert 1550 millimeters to yards.
• 63/114 Convert 45 liters to gallons.
• 65/114 Convert 8550 square feet to square meters.
• 67/114 Convert 10 kilograms per cubic meter to
  pounds per cubic foot.

15
More Practice

• 103/117 You see oranges in an Italian market
  priced at 0.8 euro per kilogram. What is the
  price in dollars per pound?
• 105/117 A French car manufacturer claims that
  its newest economy model has gas mileage of 20
  kilometers per liter. What is the gas mileage in
  miles per gallon?

16
Homework
2-B

• 2B Part I
• Pages 113-117
• 48,50,60,62,68,104,106

17
Temperature Units
2-B

• Fahrenheit (US)
• Water freezes at 32ºF, boils at 212ºF
• Celsius (International)
• Water freezes at 0ºC, boils at 100ºC
• Kelvin (Scientific)
• Water freezes at 273.15K, boils at 373.15K
• Coldest known temperature 0 Kelvin
• (-459.67ºF -273.15ºC)

18
Converting Temperatures (page107)
2-B
To Convert from Conversion Formula
Celsius to Fahrenheit   F 1.8C 32
Fahrenheit to Celsius C (F-32)/1.8
Celsius to Kelvin K C 273.15
Kelvin to Celsius C K - 273.15
19
Example
2-B

• Ex6/108 A normal human temperature is 98.6ºF
  What is that in Celsius and Kelvin?

98.6o F 37o C 310.15o K
20
Energy and Power
2-B

• Energy is what makes matter move or heat up. The
  international unit of energy is the joule.
• Power is the rate at which energy is used. The
  international metric unit of power is the watt,
  defined as
• A kilowatt-hour is a unit of energy and
• 1 kWh 3600000 joules 3.6 million joules

1 kw x 1hr 1000j/s x 60s/m x 60m/hr x 1 hr
21
2-B

• 93/116 Your refrigerator uses an average power of
  350 watts, and your utility company charges 10
  cents per kilowatt-hour of energy. How much does
  it cost to run your refrigerator for a year?

Conversion350 watts is .350 kilowatts
(why?)Usage per year in kilowatt-hours .350
kilowatts x 24 hours/ 1 day x 365 days/1 year
3066 kilowatt-hours / yearCost per year 3066
kilowatt-hours / year x .10 / 1
kilowatt-hour 306.60 per year
22
Units of Density/Concentration
2-B

• Density (e.g. material, population) describes
  compactness or crowding.
• material mass/volume (g/cm3)
• Population people/mi2
• Concentration (e.g. pollutants, BAC) describes
  the amount of one substance mixed with another.
• pollutants ppm
• BAC g/100mL (legal limit is 0.08g/100mL)

23
Example
2-B

• Ex9/111-2 Manhattan Island has a population of
  1.5 million people living in an area of about 57
  km2. What is its population density? How much
  space is available per person?

24
Example (for fun)
2-B

• Ex9/111-2(cont.) How much space is that per
  person?
• Which is roughly 6m6m, or 20 ft 20 ft

25
Example
2-B

• Ex10/112 An average-sized man has about 5L of
  blood, and an average 12-ounce beer contains 15g
  of alcohol. If all the alcohol were immediately
  absorbed into the bloodstream, what would his BAC
  be?

26
More Practice

• 79/114 The land area of the US is about 3.5
  million square miles, and the population is about
  280 million people. What is the average
  population density?
• 83/114 A typical glass of wine contains about 20
  grams of alcohol. Consider a 110-pound woman,
  with approximately 4 liters of blood who drinks
  two glasses of wine. Assuming immediate
  absorption, what is her BAC?

27
Homework
2-B

• 2B Part II
• Pages 113-117
• 70, 72, 80, 84, 94